Addressing common COVID-19 vaccine concerns with Associate Professor Nora Stelter

Concern 3: Can the COVID-19 vaccine change my DNA?

The vaccines cannot change your DNA. Both the Pfizer-BioNTech and the Moderna vaccines are messenger RNA (mRNA) vaccines. They do not enter the nucleus of the cell where our DNA (our genetic code) resides and do not affect our DNA.

So, what do mRNA vaccines do? The mRNA vaccines contain instructions that tell your own cells to make a protein (the little spike or “crown” that you see on pictures of the coronavirus) that is unique to COVID-19. These spike proteins cannot harm you or give you COVID-19. Your immune system reacts to this protein and activates a response, which includes making antibodies that can recognize and fight COVID-19 if you do get exposed.

Interesting fact: The vaccine itself only stays in your body for about 72 hours after vaccination, but your immune system now has the ability to recognize and attack the virus should it come into contact with it in the future. That doesn’t mean you can’t contract COVID-19 in the future, but it does mean that if you do, you are much less likely to become extremely ill with symptoms, become hospitalized, or die from the virus.

This activation of your immune system may cause some temporary, minor side effects, such as a slight fever, headache, aches and feeling tired. That’s ok! It means your immune system is working and gearing up for battle should it come into contact with COVID-19.

View the facts: Six common concerns about COVID-19 vaccines.

—Nora Stelter, associate professor of pharmacy practice